As a method of treating the surface of, for example, a work, there has been known a method which conducts a polishing treatment by laying a belt-shaped polishing element and the work over each other and moving the belt-shaped polishing element in a direction opposite to the traveling direction of the work. There has been known another method which conducts a polishing treatment by pressing a rotary roller-shaped polishing element in the longitudinal direction of the work having both ends that are spread out. According to these methods, the work is sent to or wound around a carrying roller or a carrying reel located upstream or downstream in a carrying direction, and is thereby carried. To carry the work, it is necessary to pull the work by a load greater than the frictional force between the work and the polishing element. The work may break due to tensile force generated in the work at this point.